iteratively key shape keys only on active object
Will this do?
import bpy

frames = bpy.context.scene.frame_end + 1

# For the active object...
ob = bpy.context.active_object
me = ob.data

# Remove ['Basis'] from a shallow copy of *ob's* shape-keys list.
kblocks = dict(me.shape_keys.key_blocks)
del kblocks['Basis']

# Keyframe shapekeys' values to 1 for the frame corresponding
# to their position in remaining list, 0 for other frames
for f in range(frames):
    for i, kb in enumerate(kblocks):
        kblocks[kb].value = (f == i)
        kblocks[kb].keyframe_insert(&quot;value&quot;, frame=f)

This may get burned down by a proper Pythonista.. :)